San Tan Valley, AZ weather in August
San Tan Valley is very hot and mostly dry in August: highs average 105°F and nights drop to about 77°F. Expect about 5 wet days. Midday heat is the main thing to plan around.
- Normal high
- 105°F
- Normal low
- 77°F
- Wet days
- 5
- 1.2 in total
- Muggy days
- 5
- dew point 65°F+
How August changes from start to finish
| August 1 | August 31 | |
|---|---|---|
| Normal high | 106°F | 104°F |
| Normal low | 78°F | 75°F |
| Chance of a wet day | 18% | 16% |
| Sunrise / sunset | 5:39 am / 7:25 pm | 5:59 am / 6:53 pm |
| Daylight | 13.8 h | 12.9 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Arizona time (no daylight saving)).
A typical August day
- 6 am85°Fdew point 61°F
- 9 am91°Fdew point 60°F
- Noon98°Fdew point 58°F
- 3 pm103°Fdew point 56°F
- 6 pm102°Fdew point 55°F
- 9 pm96°Fdew point 57°F
NOAA hourly normals (local standard time) from Phoenix Sky Harbor Intl Airport (32 mi away); average wind 7 mph.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F0 of 31
- Hot dayshigh 90°F or more31 of 31
- Muggy daysdaily mean dew point 65°F or more5 of 31
- Wet daysat least 0.01 in of rain or melted snow5 of 31
- Notable rainat least 0.10 in3 of 31
- Freezing nightslow 32°F or below0 of 31
Average days per August, counted from daily records for each year 1991-2020.
Rain in August
Normal precipitation is 1.2 in; a dry August brings about 0.8 in and a wet one about 1.7 in (25th and 75th percentiles). About 1 day brings half an inch or more.
How August varies from year to year
- Warmest August, 1991-20201994: average high 111°F
- Coolest August2005: average high 101°F
- Wettest August1993: 3.0 in
- Driest August2002: 0.09 in
- Highest reading120°F (August 7, 1995)
- Lowest reading60°F (August 31, 2000)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
August compared with July and September
| July | August | September | |
|---|---|---|---|
| Normal high | 107°F | 105°F | 101°F |
| Normal low | 77°F | 77°F | 70°F |
| Wet days | 5 | 5 | 3 |
| Comfortable days | 0 | 0 | 0 |
| Daylight | 14.1 h | 13.3 h | 12.4 h |
Highs change by -2°F from July and -4°F into September.
Nearby alternatives in August
- Drier: Yuma, AZ182 mi · high 106°F · 1 wet day
- Cooler: Tucson, AZ76 mi · high 99°F · 9 wet days
How San Tan Valley ranks in August
- Normal high7th warmest of 378 cities; 5th of 13 in Arizona
- Wet days100th driest of 378
- Comfortable days266th most of 341
What to pack for San Tan Valley in August
- Light, breathable clothing – highs near 105°F and about 5 muggy days
- Layers – afternoons near 105°F but nights near 77°F
Heating and cooling
August has 0 heating degree days and 798 cooling degree days (base 65°F), 15% of the year's total heating and cooling demand.
Questions
How hot is San Tan Valley in August?
The normal high is 105°F and the normal low is 77°F. From 1991 to 2020 the hottest August reading was 120°F (most recently on August 7, 1995).
Does it rain a lot in San Tan Valley in August?
About 5 days in August have at least 0.01 in of precipitation, and the normal total is 1.2 in. The wettest August in 1991-2020 was in 1993 (3.0 in); the driest was in 2002 (0.09 in).
Is August a good time to visit San Tan Valley?
August ranks 11th of 12 months on our comfort score for San Tan Valley (34 out of 100). It has almost no comfortable days and about 31 days at 90°F or hotter. The best months are January, February and December.
Where the numbers come from
- Temperature, rain, snowfall and snow depth: Casa Grande Nm (USC00021314), 14 mi S of the city center, 1,419 ft (103 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Frost dates: Chandler Heights (USC00021514), 9.0 mi W of the city center, 1,425 ft (97 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour: Phoenix Sky Harbor Intl Airport (USW00023183), 32 mi WNW of the city center, 1,107 ft (415 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Phoenix Sky Harbor Intl Airport (722780-23183), 32 mi WNW of the city center, 1,113 ft (409 ft lower than the city). Hourly observations, 1991-2020.
- Not available for this location: cloud cover (no station close enough or similar enough in elevation).